* Create common module for managing S3 job binaries
* Add new dependency on botocore
* Use common S3 library to create S3 job binary type for EDP
* Use common S3 library to create S3 job binary retriever
* Support storing S3 secret key in Castellan
* Document new job binary type (and foreshadow the S3 data source type)
* Unit tests for new code
Change-Id: I6781203d802305446ba1418ed6999186db4dfe9b
Partially-Implements: bp sahara-support-s3
d1287d273a